Tanaidacea (Crustacea: Peracardia) of the Gulf of Mexico. III. On the Occurrence of Teleotanais gerlachi Lang, 1956 (Nototanaidae) in the Eastern Gulf

Abstract

Teleotanais gerlachi Lang, 1956, a euryhaline member of the family Nototanaidae, known from Brazil and El Salvador, is reported from the eastern Gulf of Mexico (west coast of Florida) and the west coast of Africa (Nigeria). The species is diagnosed and illustrated. Differences between Teleotanais and the superficially similar genus Paratanais (Pantanaidae) are briefly compared and discussed. Knowledge of the distribution and systematics of members of the family Nototanaidae is very fragmentary. Of the genera so far established, Nototanais Richardson, 1906, seems to be restricted to the Antarctic-Subantarctic region and another, Tanaissus Norman and Scott, 1906, inhabits the shallow waters of the North Atlantic as well as the North Pacific. The remaining genera are monotypic. Androtanais Sieg, 1973; Metatanais Shiino, 1952; and Protanaissus Sieg, 1983, are known only from their respective type-localities. Teleotanais Lang, 1956, has been reported previously only from the coasts of El Salvador and Brazil. During our recent studies on the tanaidacean fauna of the Gulf of Mexico we discovered specimens of Teleotanais gerlachi Lang, 1956, from a sample collected by D. Bishop from the west coast of Florida. We also had access to specimens of T. gerlachi collected from the west coast of Africa (Nigeria) and this record is also included here. Teleotanais gerlachi Lang, 1956 (Figures 1-3) Synonymies: see Sieg, 1983: 418-419. Material Examined 11 09 ( 10 99 in coll. Heard, 1 9 in coll. Sieg, dissected) from Crystal River, Florida (2855'N, 8240'W); Highway 40 off US Highway 19 ,4 miles west of Yankeetown, from oyster rock [together with 4 specimens of Hargeria rapax (Hargen 1918); D. Bishop, collector. Approximately 200 specimens (neuters, females) from Elechi Creek near Port Hartcourt, Nigeria (0447.3'N, 0698.6'E); high intertidal, on Avicennia pneumatophores, among green algae and Bostrychia, mesohaline; co-occurring with Sinelobusstandfordi(Richardson, 1901);C. B. Powell,collector] . Diagnosis Antenna I 4-jointed, first joint at most Manuscript received July 5,1983; accepted October 3, 1983. twice as long as second, fourth joint relatively short with 2 aesthetascs at tip (Figure 1);antenna I1 6-jointed, third joint elongate (Figure 1); maxilla 1 with 11 spines (Figure 2); basis of maxilliped totally fused (Figure 1);propodus of pereopods with 1-3 distal setae, 2 long sternal setae and 1 short tergal seta; basis of pereopods 4-6 thickened (Figure 3); endopodite of pleopods narrowing at junction with basis, without a lateral marginal seta, separated from others by a gap (Figure 1); uropods biramous, endopodite and exopodite 2-jointed, exopodite longer than first joint of endopodite (Figure 1). Remarks Teleotanais superficially resembles Paratanais Dana, 1852, because both genera have a 4-segmented antenna I and uropods with 2-jointed exopodite and endopodite. In Paratanais the last joint of antenna I is elongate and longer than the second and third joint combined, while in Teleotanais the last joint is distinctly shorter. Another difference is found in antenna I1 which in Paratanais has a short, thick third joint with strong outer spine, while in Teleotanais the third joint is elongate (as long or longer than the fourth joint) and lacks an outer spine. Maxilla 1 bears in Teleotanais eleven and in Paratanais nine terminal spines. The maxillipeds of the two genera are distinctly different. Since Paratanais belongs to the Family Paratanaidae the basis of the maxilliped is unfused; whereas it is completely fused in Teleotanais (Nototanaidae). Additionally in Paratanais the endite of the maxilliped is broad and expanded laterally, fused with the basis (Sieg 1981: 1274 Figure 2). In Teleotanais the endite is small and of normal shape with a relatively long seta at the outer margin of the endite, which we believe to be a characteristic of this genus. The pleopods of Teleotanais and Paratanais are distinctly different. In Teleotanais specialized setae on the distal part of the exopodite and the separate seta inserted proximally at the outer margin of the exopodite are missing; these setae are present in Paratanais and all other genera in the Paratanaidae. The chela of the chelipeds of Teleotanais and Paratanais also have distinctly different shapes.